Manufacture of artificial silk



March 1 1927. 1,619,768

F. W. SCHUBERT MANUFACTURE OF ARTIFICIAL SILK Filed June 21, 1926 WW/MQ' w). w m/ I Patented Mar. 1, 1927.

UNITED STATES PATENT OFFICE.-

'IRIEDRIGH WILHELM SCHUBERT, F APPERLEY BRIDGE, NEAR BRADFORD, ENG-LAND, ASSIGNOR TO BRYSILKA, LIMITED, OF APPERLEY BRIDGE, NEAR BRAD-FDRD, ENGLAND.

MANUFACTURE OF ARTIFICIAL SILK.

Application filed June 21, 1926, Serial No.

This invention relates to the manufacture of artificial silk fromcuprammonia cellulose solutions and has particular reference to theproduction of artificial silk threads by the stretch spinning processwherein the spinning of the thread is effected by passing or conductingthe viscous solutions or liquid through a single precipitating orcoagulating liquor. The chief object of the present invention is todispense withthe feeding of the liquor from above under pressure.

According to the present invention the precipitating or coagulatingliquor through which the filaments pass or are conducted is supplied tothe spinning vessel from below under atmospheric pressure in accordancewith the drawing out of the .filaments and the speed of the collectingdevices on or by which the filaments are stretched or spun during thewinding, the liquor being circulated or replenished as a result of thesurface friction of the thread through the liquor and in a directionopposite to the movement of the filaments. Thus in an embodiment of 25the invention the precipitating liquor is supplied to .a tankopen to theatmosphere and into which the spinning vessel depends with itslower'open end submerged in the liquor. The upper end or head of thespinning vessel may be fitted with the usual spinneret top and haveconnected thereto a suction pipe controlled in any appropriate mannerfor exhausting the air.

Referring to the drawing where is diagrammatically illustrated apreferred manner of carrying out the invention, 1 indi cates a spinningvessel having a lower opened end which extends into a trough 2, and hasits upper end closed and arranged to receive a spinneret nozzle 3, and asuction pipe 4, the latter being arranged to exhaust the air in thevessel so as to maintain a vacuum in the top thereof. The filaments orthreads 7, as they leave the spinneret nozzle 3, pass down the vessel 1,around the guide roller 5, and onto a collecting or winding roller 6.The circulation of the precipitatin liquid within the spinning vessel 1and t e trough 2, is effected by the surface friction of the filamentsthrough the liquid, and the atmospheric pressure on the liquid in thetrough, thus causing the liquid to circulate in a direction opposite tothe move 117,533, and in Great Britain July 2, 1925.

ment of the filaments and as indicated by the arrows in the drawing.

In operation the filaments passing or being drawn through the liquorgradually become coagulated and a proportion or quantity of the liquoradjacent the filaments as :the latter descends has a tendency to followthe direction of the filaments, being replaced or counteracted by theupward flow from the tank, the liquor being thereby circulated orreplenished as a result of the surface friction of the thread throughthe liquor. The movement of the liquor adjacent said filaments will becontrolled according to the speed at which the filaments are drawn fromthe spinning vessel, said speed being controlled or governed by thevarious factors or conditions affects mg the viscosity of the solution,the percentage of cellulose, number of filaments, the percentage ofammonia and the strength and temperature of the caustic soda solutionemployed as the coagulating bath. The suction pipe at the upper end ofthe spinning vessel may have suitable control devices for regulating orvarying the suction during the starting u of the machine until the airin the funne is displaced or removed. Other than the spinning nozzleopenings and the suction inlet to the head of the spinning vessel the uper end of the latter will be entirely closes, thus the entire supply ofp'reci itating or coagulating liquor 1s introduce only in a directionopposite to the movement of the filaments in contradistinction to knownprocesses wherein the liquor acts in two directions or in a directionfollowing that of the filaments or where the coagulating liquor'is fedto the top of and down the funnel. The. filaments during or after thestretch spinning process may be wound on to bobbins, reelsor otherdevices after passing through suitable washing fluids and either afteror before twisting. The twisting of the filaments may thus be effecteddurm the stretch spinning stage and immediatrfiy prior to being wound onto the bobbins, reels or like devices.

1. A new and improved rocess of manufacturing artificial silk w ichconsists in liquid, delivering the filament to a collecting devicethrough an opened top trough into which the spinning vessel extends sothat the coagulated liquid will be supplied to the spinning vesselthrough the bottom thereof by atmospheric pi'essure and in accordancewith the drawing out of thefilament and the speed of the collectingdevice, the liquid be ing circulated due to the surface friction of thethreads through the liquid in a direction opposite to the movement ofthe filaments.

2. A new and improved process of manufacturing artificial silk whichconsists in in-" troducing a cuprammonia cellulose Solution filamentinto a spinning vessel containing a precipitating liquid, delivering thefilament to a revolving collecting device through an opened top troughinto which the spinning vessel extends so that the precipitating liquidvwill be supplied to and clrculated in the spinning vessel through thebottom thereof by atmospheric ressure and in accordance with the drawingout of the filament and the speed of rotation of the collecting device,the liquid being circulated due 'to the ,surface friction of thefilaments through the liquid in a direction opposite to the movement ofthe filaments. FRIEDRICH WILHELM SCHUBERT.

